Newbee here, hi to all. I am wondering if there is anyone on the forum who may be able to shed some light on a product that is worn like a watch but is claiming to accurately measure vibration magnitudes being emmited from a hand held tool, on the surface thhe device looks wonderful as there is no real input required from the user but where i see a problem is this. If when the tool is operated you touch the motor housing at the grip points, the vibration is very strong, if i then touch the back of the hand that is gripping the tool the vibration is considerably less, then if i touch the watch on the wrist there is hardly any vibration being felt and i am trying very hard to try and figure out how a monitor on the wrist takes into account all hand sizes and shapes, gloves or no gloves worn, and has an algorythm to make accurate readdings. An important note is that the company has some very detailed disclaimers basicaly imdemnefying them of any blame owing from their device useage... in short you cant depend on their date in a court of law and theyy wont be responsible if you do use it. As i understand it, the HSE has a rather cool paper on this and its L140, it quite clearly states in it that measurement of magnitudes needs to be on thee tool and at the grip points, but even though that is pretty clear, i am being led to believe that its only a guide and we dont have to follow it???. If anyone has any thoughts on this, i would really love to hear them. Best regards. 

Hi Mike, I've spoken to HSE on this matter and they aren't impressed with these devices, and they cost a lot of money. Better to follow the guidance within L140, although it is a bit of a read. Without going into a load of detail all these devices do is tell you the vibration exposure, which as previous posts have highlighted have a number of variables, and therefore you pay a fortune for something you don't need and is unreliable. There is nothing in the legislation that says you can't use the manufacturers vibration magnitude levels, albeit they aren't great, but you can use them. The key is to demonstrate that you have controlled the risk. Again from expierience with HSE I had the following:

• Purchasing policy favoured lower vibration tools (note, Reg 6 of the noise and vibration regs are the same and if one is higher than the other then that's a conflict HSE can't solve. So I found out when I asked them) 
• Clear maintenance of tools records
• Evidence of risk reduction e.g. we had a corer that was over 24m/s but we bought a jig and it reduced it to negligable
• Control - all hired tools come through a single point with vibration data and date of last and next inspection, which is recorded, before being issued to the workers
• Surveillance - make sure that you are doing it when your risk assessment shows your workers are exposed above 100 points.

Hope this helps :o)

Hi Mike,

We currently use a wrist worn system to monitor and log our vibration exposure levels. The system we use has RFID tags which can be set to the actual vibration level of the tool. We use a calibrated vibration measuring device to get acurrate measurments of the job process. This allows us to get actual usage real time data :-).

The wrist worn monitor has it's' own accelerometer and has been surprisingly close to the real measurments. We use it more to give us guidance on when the tool is starting to 'Drop off' and need maintenance. It also helps if a tool is used without connecting as some level of vibration is registered.

The systems are proving extremely good at helping us control our vibration exposure. We have gone from an exposure of close to 350 points per employee to each person being under 100 points, although I do have full support from the managment team too!

The tools should be used in conjuction with a specific readings for the job, but on the other hand it's a dam sight better than doing nothing at all. Hope this helps

Nick

Anything with a lengthy list of disclaimers means the manufacturer has no confidence in its own product so why should the consumer?

I always work out my own HAVS calculations without need for expensive watches or monitors, Not only do you spend more time than neccessary on that particular job, but the necessary ongoing expense and calibration every so often makes this an expenses, Long winded option to something which is pretty easy to calculate, Even the HSE have an online Calculator for you to use.

Its a Gimmick

Am I right in saying that the manufacturers data on vibration is not accurate data. They also give a K value, which I have been told is the error in the data, so it could be + or - the K value